Field of the Invention
The present invention relates to a nanopipette including a membrane containing a saturated ionophore and, more specifically, to a nanopipette including an ion selective membrane exhibiting ion selectivity by containing a saturated ionophore. The present invention relates to a method for manufacturing a nanopipette including a membrane containing a saturated ionophore and, more specifically, to a method for manufacturing a nanopipette including an ion selective membrane exhibiting ion selectivity by containing a saturated ionophore. The present invention relates to an ion measurement apparatus using a nanopipette including a membrane containing a saturated ionophore and, more specifically, to an ion measurement apparatus including an ion selective membrane, which exhibits ion selectivity by containing a saturated ionophore, inside a nanopipette.
Related Art
Ion selective electrode (ISE) is a kind of membrane electrode having a membrane selectively responding to a particular ion in a solution, and the concentration (activity) of ions can be obtained by measuring the electric potential on an interface between the membrane and the solution. Such an ion selective electrode is equally said a potentiometric ion sensor. The ion selective electrode includes an ion selective membrane. The ion selective membrane is in direct contact with the analyte sample to sense the particular ion, thereby generating a voltage, and thus the ion selective electrode is the most important part in the ion selective electrode.
The ion selective electrode can measure the concentration of a particular ion existing in a sample solution, and thus is used in many fields, such as food chemistry, fermentation processes, environment analysis, or clinical chemistry, for example, hemodialysis, hematoma electrolyte continuous automatic measurement, or extracorporeal blood. Meanwhile, the local ion concentration may be measured using a scanning ion-conductance microscope (SICM) employing a nanopipette which can be controlled at the nano-scaled unit, but since the SICM senses the overall ion current, that is, total ion current, it is not easy to confirm a particular ion distribution.
As for the existing ISE method, although the ions to be detected can be measured, the diameter of a pipette tip portion is very large to the millimeter (mm) unit and the concentration range of the measurable ions is also large, and thus, the ISE method has disadvantages in that the measurement of high concentrations is allowable. However, ion filter electrodes have been recently developed in order to solve the size-related problems and the ion detection even at low concentrations.
The ion filter electrode has a membrane type of plasticized PVC formed inside a pipette, and the diameter of a pipette tip can be reduced to several hundred nanometers. However, the ion filter electrode has disadvantages in that an ionophore existing in the PVC membrane cannot be reused after use, and the concentration of one type of desired ion cannot be measured in an aqueous solution containing three or more types of ions.